/*
* Conditions Of Use 
* 
* This software was developed by employees of the National Institute of
* Standards and Technology (NIST), an agency of the Federal Government.
* Pursuant to title 15 Untied States Code Section 105, works of NIST
* employees are not subject to copyright protection in the United States
* and are considered to be in the public domain.  As a result, a formal
* license is not needed to use the software.
* 
* This software is provided by NIST as a service and is expressly
* provided "AS IS."  NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED
* OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT
* AND DATA ACCURACY.  NIST does not warrant or make any representations
* regarding the use of the software or the results thereof, including but
* not limited to the correctness, accuracy, reliability or usefulness of
* the software.
* 
* Permission to use this software is contingent upon your acceptance
* of the terms of this agreement
*  
* .
* 
*/
package gov.nist.javax.sip.parser;
import gov.nist.javax.sip.header.*;
import java.util.*;
import java.text.ParseException;

/**
 * Parser for SIP Date field. Converts from SIP Date to the
 * internal storage (Calendar)
 *
 * @version 1.2 $Revision: 1.10 $ $Date: 2007/01/28 17:33:15 $
 */
public class DateParser extends HeaderParser {

	/**
	 * Constructor
	 * @param date message to parse to set
	 */
	public DateParser(String date) {
		super(date);
	}

	protected DateParser(Lexer lexer) {
		super(lexer);
	}

	/**
	 * Parse method.
	 * @throws ParseException
	 * @return  the parsed Date header/
	 */
	public SIPHeader parse() throws ParseException {
		if (debug)
			dbg_enter("DateParser.parse");
		try {
			headerName(TokenTypes.DATE);
			wkday();
			lexer.match(',');
			lexer.match(' ');
			Calendar cal = date();
			lexer.match(' ');
			time(cal);
			lexer.match(' ');
			String tzone = this.lexer.ttoken().toLowerCase();
			if (!"gmt".equals(tzone))
				throw createParseException("Bad Time Zone " + tzone);
			this.lexer.match('\n');
			SIPDateHeader retval = new SIPDateHeader();
			retval.setDate(cal);
			return retval;
		} finally {
			if (debug)
				dbg_leave("DateParser.parse");

		}

	}

	
}
